Birdsong is an excellent model system for investigating the neural correlates of sensorimotor integration and learning of complex behavior. Much attention has focused on the study of auditory processes in the vocal motor pathways; these efforts have largely occurred in adult, anesthetized birds after learning has already occurred. A recent breakthrough in the sponsor's lab allows chronic single-unit recordings in singing birds; the proposed research will apply these techniques to study sensory and motor activity in song system nuclei in two sets of experiments. 1) motor activity will be characterized in HVc and RA (nuclei involved in moment to moment control of song), and in Area X and 1MAN (nuclei necessary for song learning) in juvenile zebra finches (Taeniopygia guttata) during song learning. Development of the temporal hierarchical organization of the adult motor pathway will be studied. 2) Auditory activity will be characterized in the same nuclei, allowing the distribution of song system auditory neurons and development of auditory selectivity for the bird's own song to be studied. Use of chronic techniques will address the recent finding that anesthetics significantly alter the distribution of song system auditory activity.